코코피트 및 톱밥을 팽화제로 사용한 음식폐수의 고속퇴비화 비교 연구 = A Comparative Study on High Efficient Composting of Food-Wastewater Using Cocopeat and Sawdust as Bulking Agent

다국어 초록 (Multilingual Abstract)

While food wastewater generated from food waste treatment plant has been mostly disposed with ocean dumping, the government policy has been promoted for its land treatment by 2013. Food wastewater contains a high portion of water and organics. High water content causes a lot of difficulties in composting process.
This study was carried out to find out the optimum design conditions in aerobic composting of food wastewater using cocopeat and sawdust as bulking agents.
This study was carried in three steps, first, experiment to determine initial water content for compost, second, comparative experiment using cocopeat and sawdust with control of air supplement and temperature of compost, and third, continuous compost experiment to maximize treatment of food wastewater.
According to the result of former experiments to determine the initial condition, the temperature could not reach to 50℃ in composting using sawdust with water contents of 65% and leachate was generated in composting process with moisture content of 75%, which was recycled to compost body immediately. It took lot of time to reach to temperature of 50℃ and the composting could not easily processed.
In compost process using cocopeat with 75% of moisture content, leachate was not generated, and air was easily supplied for aerobic condition, and temperature has been early reached above 50℃, but with the lack of organics within reactor the temperature dropped to 50℃ after 42 hrs of reaction time.
The comparative experiment using various bulking agents, adjusted 75% of initial moisture content, with air supplement of 1.72ℓ/min, the temperature of 50～60℃ in compost could be maintained. With recycling of leachate from compost into reactor, the temperature of compost using sawdust arrives above 40℃ and maintained 50℃ for 3 days.
The compost using cocopeat has high water holding capacity. There was no leachate in compost process with 75% of moisture content. Air supplied easily into aerobic composting because of high portion of porosity. When the compost temperature reached above 40℃, additional 1kg of food wastewater was loaded into compost and maintained temperature above 50℃ for 3days. Final C/N ratio of compost using sawdust and cocopeat was 30.7 and 16.4, respectively. Total reduction of VS was 35.5% and 29.7%, and total reduction of weight was 30.0% and 24.4%.
As bulking agent cocopeat was more adequate than sawdust. The final pH of compost were 8.2 and 8.3, and C/N ratio were 12.4 and 11.6, and total reduction of VS were 40.0% and 41.3%, and total reduction of compost weight were 34.8% and 29.3%. The throughput of food wastewater per 1kg of bulking agent were 6.57kg and 8.55kg. It was proper to compost with moisture content of 75% to maximize treatment of food wastewater.
The result of this study can provide the basement for development of price-competitive recycling technology by means of composting of food wastewater, and it seems to contribute to cost reduction in food waste treatment plant, to inland process of food wastewater, and to realization of recycling policy.

목차 (Table of Contents)

• I. 서론 1
• 1. 연구 배경 1
• 2. 연구 목적 3
• 3. 연구 내용 및 범위 4
• II. 이론적 배경 5
• 1. 음식물폐기물의 발생 및 처리 현황 5
• 1.1 음식물폐기물의 발생원 5
• 1.2 음식물폐기물의 발생 현황 6
• 1.3 음식물폐기물의 처리 현황 8
• 2. 음식폐수의 발생 및 처리 현황 9
• 2.1 음식폐수의 발생 특성 9
• 2.2 음식폐수의 발생원 10
• 2.3 음식폐수의 발생 및 처리 현황 10
• 3. 음식폐수 처리 관련 정책 15
• 3.1 해양 배출 관련 정책 15
• 3.2 육상 처리 관련 정책 16
• 4. 유기성폐기물의 자원화 방안 19
• 4.1 음식물폐기물의 자원화 기술 19
• 4.2 음식폐수의 자원화 방안 30
• 5. 고온 호기성 미생물을 이용한 퇴비화 34
• 5.1 고온 호기성 퇴비화 공정 34
• 5.2 호기성 퇴비화의 영향인자 43
• 5.3 음식 폐수의 성분 특성 55
• 5.4 퇴비의 규격 56
• Ⅲ. 실 험 57
• 1. 실험 개요 57
• 2. 실험장치 및 분석방법 58
• 2.1 실험장치 58
• 2.2 분석기기 및 방법 59
• 3. 시료 성상 64
• 3.1 음식폐수의 성상 64
• 3.2 팽화제의 성상 65
• 4. 실험 방법 67
• 4.1 초기조건 결정 실험 67
• 4.2 팽화제간 비교 실험 68
• 4.3 음식폐수 추가 처리 실험 69
• Ⅳ. 실험 결과 및 고찰 70
• 1. 초기조건 결정 시험 70
• 1.1 실험 개요 70
• 1.2 톱밥을 팽화제로 이용한 퇴비화 71
• 1.3 코코피트를 팽화제로 이용한 퇴비화 85
• 1.4 고찰 98
• 2. 본 실험 101
• 2.1 실험 개요 101
• 2.2 팽화제간 비교 실험 102
• 2.3 음식폐수 추가 처리 실험 135
• 2.4 실험 결과 정리 148
• 2.5 고찰 149
• 3. 경제성 평가 155
• Ⅴ. 결 론 157
• Ⅵ. 참고문헌 163
• Abstract 169